1. Technical Field of the Invention
The present invention relates to the production of products containing dehydrated legumes. More particularly, this invention is directed to a process for producing dehydrated bean products containing descernible bean pieces. The dehydrated products are capable of essentially instant, substantially uniform reconstitution upon the addition of water.
2. Discussion of Material Information
Legumes are a plentiful and economical source of nutrition. Beans, peas, and other leguminous materials have been conventionally prepared using a variety of procedures to produce different products which are now staples in our diet. In recent years, numerous attempts have been made to dehydrate leguminous materials to render them quickly reconstitutable to permit them to be easily prepared for consumption, for example into soups and similar products.
U.S. Pat. No. 1,088,741, STEPHENS, illustrates a process for the preparation of a dehydrated bean product which involves first parboiling beans in an aqueous solution containing sodium bicarbonate, followed by rinsing and cooking the beans in salt water until tender. The cooked beans are then pressed into flakes and dried until crisp and brittle. The bean flakes may be prepared for consumption by pouring boiling water over them.
U.S. Pat. No. 2,343,149, KRAUSE, Jr., is another example of a process which relates to the preparation of legumes, such as peas and beans, to produce a completely precooked and thoroughly dehydrated powder. The process involves exposing precooked, pulpy leguminous material to high heat and pressure between rollers to completely dehydrate the material into flake form. The dehydrated flakes may then be reduced in particle size to a powder, for example using a hammer mill. The dehydrated flakes or powder may be mixed with suitable seasonings, salt, etc., to form a concentrate which will dissolve in water to form a thick puree-type product.
U.S. Pat. No. 2,657,999, RAUCH, is directed to the preparation of precooked peas and beans in other than powder form. The process involves subjecting fully saturated, cooked beans to the action of a hammer mill to reduce them to a particulate form having a size not substantially larger than 1/8 inch. The particulate product is spread onto drying trays and dehydrated to a moisture level of less than about 7%. The resultant dehydrated bean and pea material may then be blended with prepared fatty materials, salt and seasoning in the preparation of, for example, a soup mixture.
U.S. Pat. No. 4,251,558, KOBAYASHI et al., relates to the production of a dry, granular bean paste. The process involves the extrusion of bean paste into a vacuum chamber to dehydrate the same. This is followed by further dehydration and treatments to reduce the particle size of the extrudate.
More recently, refried beans have become generally more popular as a food item, particularly in the food service industry, such as restaurants which specialize in Mexican-style meals. In an attempt to provide an alternative to the procedures involved in the preparation of refried beans from beans in their natural state, canned refried beans and dehydrated bean powders have been developed.
U.S. Pat. No. 4,407,840, LATHROP et al., is directed to a process for producing a dried bean product which is disclosed as being instantly reconstitutable to form a product having the flavor, color, and texture of conventional refried beans. The process involves cooking raw beans in the presence of water. The beans are preferably blanched in their dry state prior to cooking in a pressure cooker. The beans are discharged from the pressure cooker in such a manner so that the pressure drop is almost instantaneous and the resultant flashing-off of water as steam when the beans are removed from the pressure cooker, causes the beans to undergo a substantial physical degradation. A bean slurry containing finely divided bean mash, whole bean pieces, and bean skin particles is disclosed as being formed as a result of such degradation. The slurry may also be subjected to a milling procedure to render it more suitable for subsequent dehydration. Dehydration is preferably carried out on single or double drum dryer to a moisture content of less than about 6% by weight. The dried product, having a loose pour density of about 0.24 to 0.28 gm/ml, is disclosed as being instantly reconstitutable in either hot or cold water to yield a product simulating typical refried beans.
Such prior art attempts to produce instantly reconstitutable bean and pea products have not been completely successful in arriving at a product which will simulate the organoleptic characteristics of a product freshly made from beans in their natural condition. Dehydrated powders, for example, tend to reconstitute into a smooth paste which does not have a discernible crunchy texture that products produced from natural raw material exhibit. Moreover, dehydrated bean powders tend to cake during storage and are difficult to reconstitute uniformly without vigorous mixing and agitation.
The preparation of bean products from natural raw material is often found to be unsuitable in situations which require frequent preparation of large volumes of the food product, for example in restaurants. This is largely due to the time consuming procedure involved in the conventional preparation of bean products, such as refried beans. For example, a typical on-site preparation of refried beans in a restaurant involves inspecting and washing the raw material in fresh water prior to mixing the clean beans with measured quantities of water, salt, and lard. The mixture is usually cooked in a pressure cooker for about two hours following which the ingredients are mixed to the desired consistency. Afterwards, the mixture. which usually includes cooked bean fragments, must be stored in a refrigerator until it is refried in preparation for consumption.
Products such as these prepared in bulk often suffer from inconsistencies in quality, including moisture content, because of deviations from proper weighing and measuring procedures. In preparations in which all of the procedures are performed by hand, stirring the beans to mash them will vary from person to person. Moreover, strict attention must be paid to burner control in order to ensure proper evaporation of water during cooking and to prevent scorching from occurring. In addition, the degree to which the beans are cooked will vary from batch to batch depending on the way in which the foregoing procedures are carried out. All of this contributes to inconsistencies in product quality. Furthermore, pressure cooking and handling of hot refried beans can be dangerous when performed in a typical restaurant kitchen due to limited floor space, heavy traffic, and operating personnel who are often unfamiliar with pressure cooking techniques.